We know exactly what we are going to get from the Boston Celtics in Game 6 Friday night — they are going to defend hard, Kevin Garnett is going to crash the boards and get his points, Paul Pierce will create looks for himself. They will scrap, that’s what champions on the verge of elimination do.

What are we going to get from the Knicks on offense?

That is the simple question of this series. It’s not about wearing black or what anybody said about Carmelo Anthony’s wife. That’s the sideshow the Knick’s can’t get caught up in (but have).

New York was strong on offense in the regular season, an offensive rating of 106.6 points per 100 possessions; they shared the ball well and especially during their late-season winning streak moved the ball from strong to weak beautifully.

Boston’s stout defense was always going to be a challenge, but the Knicks have averaged 96.3 points per 100 possessions in the playoffs.

The reason is they have fallen back in love with isolation basketball — which is what the Celtics defense is set up to stop.

In the regular season, the Knicks averaged 15 isolation sets a game (well above the league average of 10), but in this series they have averaged 26 a game (stats via ESPN).

By the time you get to the playoffs against a good defensive team, they are going to take away your first option — whatever the primary goal of your offensive set is will not be easy to get. Nor will the second by the time you are five games into a series — the other team has studied and seen what you want to run. You need to beat good teams with your third, your fourth options.

But the Knicks offense has broken down when it gets past the first couple options, so they throw the ball to Carmelo Anthony or J.R. Smith and ask them to create something. That’s hard to do against Boston.

This is not to say Boston has no say in the outcome tonight — at home they could get a big night from Jeff Green or Jason Terry, giving them enough scoring to overwhelm the Knicks for a night.

But New York has to win one of two to advance. New York is the better team, but it has to be the best version of itself to advance. It has to live up to its promise and not revert to isolation basketball.

Let’s start with the injury report: No Chauncey Billups and maybe no Amar’e Stoudemire for the New York Knicks. No Shaquille O’Neal for Boston, but that has not mattered.

New York always had just a puncher’s chance in this series — they were less talented but if Stoudemire could take over one game, if Anthony took over another, if Billups drained some big late shots then….

Nope. The Knicks landed their haymakers in Game 1 (Stoudemire was brilliant, so the Knicks went away from him in the final two minutes) and Game 2 (‘Melo went off) and it didn’t matter. The Celtics withstood the blows, executed late and won. Billups has been out since tweaking his knee late in Game 1 and been a non factor.

Game 3? That was pretty much where the talent levels of these teams are at. Boston was up 9-0 to start the game and it never felt any closer than that in a blowout win.

No Stoudemire and Billups should mean New York gives the Celtics the Full D’Antoni and just tries to run the into the ground. Run on everything. Makes and misses. But that’s probably not what happens, the ball will stick when it hits ‘Melo’s hands, the Celtics will run a hard double team at him and we’ll see what Shawne Williams and Toney Douglas can do. And Jared Jeffries, don’t forget Jared Jeffries. Meanwhile Ray Allen and Rajon Rondo will continue to have good series.

Boston knows the Heat are next and the more time off (likely a week, rumor is next weekend is when that series will start) the better. Their old legs could use it. But the Celtics are fully capable of going through the motions and losing — remember last year’s playoffs they were up 3-0 twice and lost Game 4 both times — forcing a Game 5 on Tuesday. It really is a matter of how focused they are on defense.

Everyone, including Spike Lee, knows how this movie ends. Boston is the better team, the Knicks wanted to make the playoffs and generate some excitement this season and they did that. The only question now is how long it drags out. And that is a matter of focus from the Celtics and how many Knicks can be put out on the court Sunday.

“It’s a strained back muscle,” he said. “So there’s a chance of straining it more, there’s a chance of overcompensating and having another injury. So there’s definitely some risks of playing with a strained back. And I’m not sure we want to take that risk right now when we have such a great future ahead of us.”

If he does not start, Shawne Williams will start. And you will not hear the name Carmelo Anthony without the words “double team” mentioned in the same sentence.

“He’s not playing [Sunday],” said Rivers. “We didn’t do anything to see honestly. We didn’t practice, we just walked through. I’m not going to put him out on the floor.”

Not a big deal for Sunday. Boston blew out the Knicks in Game 3 at Madison Square Garden and now the series is merely a formality. Maybe it ends Sunday, maybe they go back to Boston for a Game 5 on Tuesday. But either way the writing is on the wall.

But the Celtics will need Shaq against the Heat in the next round and getting him some run before being thrown into that fire would have been a boost. The good news is rumors are it will be next weekend before that series starts, so Shaq will get plenty of time to get right.

The NBA playoffs return to the heart of New York, to Madison Square Garden Friday night after seven long years away and will be welcomed back like the prodigal son.

Celebrities will ring the court — including Spike Lee in some all-orange disaster of an outfit — and profanity-laced chants will rain down on the Celtics. There will be real energy, real passion, real optimism, a real New York feeling that the NBA playoffs have sorely missed. Carmelo Anthony bullied his way out of Denver to be here for it and told ESPN New York this will be, um… well, he can’t use the word he wants to for a description.

“I’m pretty sure it will be crazy,” Carmelo Anthony said. “I think crazy is an understatement but that’s the word I’m going to use right now.”

The only thing this hyped and with this many injuries in New York in the last seven years was Spider-man the Musical. New Yorkers are just hoping they like Friday night’s show better.

The Knicks have landed two solid punches on the Celtics in the first two games, one from Amar’e Stoudemire in Game 1, another from Carmelo Anthony in Game 2.

In both cases the Celtics staggered, found their footing, then executed better at the end and got the wins. The Celtics played like a team with a ring — getting Ray Allen a key late-game shot — the Knicks closed out games like a team that has missed the playoffs for seven years. When Jared Jeffries is taking your clutch shots in the final minutes, you’re doing it wrong.

To do it right, the Knicks need to get healthy.

Stoudemire is expected to go, although don’t expect him to do any pregame dunks this time. That would help, although at some point he and Carmelo need to play together and not next to each other for the Knicks to truly evolve. Chauncey Billups seems unlikely but is officially a game-time decision. (Shaquille O’Neal is a no for Game 3 for Boston, there is a slight chance he plays on Easter.)

Expect the Celtics to be physical with Stoudemire early — they are physical with everyone in the paint but they will step that up a little to test Amar’e early. Also, Carmelo Anthony can expect hard double teams early as Boston does not what him to get going — make someone else beat them.

Where the Knicks need to beat them — where this game will be decided — is in the paint and on the glass. The Knicks were the better, stronger team inside in Game 2 and that as much as ‘Melo’s heroics was the reason the Knicks had a shot at the end. A shot Jeffries had to take, but a shot nonetheless.

If you’re looking for a Knicks killer, watch Ray Allen. He is 7-of-9 from three in this series, he has his stroke back. Expect Rajon Rondo to get him the ball more… well, you should expect that. But Rondo has been a little unpredictable lately. Which is another thing to watch.

Kevin Garnett has to be big, but he needs to get some help. Jermaine O’Neal was a huge factor in Game 1 and a ghost in Game 2. They need him to control the paint, they need to turn the Knicks into jump shooters.

Toney Douglas and ‘Melo can get hot and drain those jumpers, and when then do Madison Square Garden will explode. But it is not a sustainable way for the Knicks to win.

The Knicks have to win. It is must win, and desperate teams often find a way. Or, this could be Spider-man the Musical.

The only thing we know for sure is that in a series that has been crazy and loud, the volume is about to go up.